1. Field of the Invention
Embodiments of the present invention relates to a display device, and more particularly to flexible display device. Embodiments of the present invention are suitable for a wide scope of applications. In particular, embodiments of the present invention are suitable for providing a substrate module for a flexible display device and a method of manufacturing a flexible display device using the substrate module.
2. Description of the Related Art
Recently, demand has been increasing for display devices that are light, thin, as well as wide and flat. A glass substrate is generally used in most flat display devices. The glass substrate is highly brittle. Accordingly, such display devices require a protective layer for the glass substrate. Moreover, such display device are difficult to bend for displaying an image.
A flexible substrate has recently been developed to fabricate a flexible display device. The flexible display device includes a plastic material or a metal foil in addition to the flexible substrate. However, displaying an image on the flexible display device is difficult in comparison to a glass substrate. The flexible substrate of the flexible display device often causes a misalignment when thin film transistors, pixel electrodes, and conductive lines are formed on the flexible substrate. Accordingly, the related art flexible substrate is usually attached to a hard substrate such as a glass substrate. Then, a thin film forming process and a thin film patterning process are performed.
The flexible display substrate includes a base substrate, a flexible substrate, and an adhesive part. The base substrate is generally a glass substrate. The base substrate prevents the flexible substrate from bending during the thin film forming process and the thin film patterning process.
The adhesive part is interposed between the base substrate and the flexible substrate to attach the flexible substrate to the base substrate. The flexible substrate provides some flexibility to the display device. The flexible substrate does not bend during a plurality of processes for manufacturing the flexible display device because the flexible substrate is attached to the base substrate. After forming and patterning the thin film, the flexible substrate is separated from the base substrate to complete the manufacture of the flexible display device.
However, during a cleaning and an etching process of the flexible substrate, the flexible substrate contacts to various etchants or chemicals. For example, a metal layer and a photoresist pattern are formed on the flexible substrate to form a pattern on the flexible substrate. Then, the metal layer is etched using the photoresist pattern as an etch mask. Various etchants or chemicals are used to pattern and remove the photoresist and pattern the metal layer.
When the flexible display substrate including the base substrate, the adhesive part, and the flexible substrate contacts the etchant. Hence, the adhesive part between the flexible substrate and the base substrate may be etched or dissolved by the etchant. Accordingly, an edge portion of the flexible substrate may be separated from the base substrate.